1. Field of the Invention
The present invention relates to an articulated support with lateral movement for high-voltage or medium-voltage electrical plant.
To be more precise, it relates to a support for high-voltage or medium-voltage electrical plant comprising four columns placed on a support surface and connected in pairs by four assemblies of crossmembers.
2. Description of the Prior Art
This kind of support is used in shielded electrical plant housed in a metal enclosure, as shown in FIG. 1.
Such plant includes a shielded horizontal circuit-breaker 2 connected at each of its two ends by way of a connecting compartment 8 to a shielded disconnector 3. The connecting compartment 8, carrying a toroidal current transformer 6, is closed in a manner known in the art by insulative cones. An overhead line bushing 11 is mounted on top of each disconnector 3 which, together with the bushings and ancillary plant, are supported by a support 1 resting on the ground.
In the above kind of prior art plant, each support 1 is fixed to the ground directly or indirectly and comprises four substantially vertical columns connected in pairs by four crossmember assemblies. Each crossmember assembly comprises two crossmembers that cross over each other, as shown in FIG. 1, for example. The columns and crossmembers are rigidly connected.
It might prove necessary to demount the circuit-breaker 2 rapidly, for example in the event of a malfunction, without deinstalling the other plant (disconnectors and overhead line bushings). In particular, it would be particularly advantageous for the disconnectors and overhead line bushings to remain pressurized with dielectric gas and live. At present, demounting the circuit-breaker interferes greatly with the operation of the electrical substation in which the plant shown in FIG. 1 is installed, as it implies disconnecting at least one of the two overhead lines and demounting the bushing-disconnector-framework assembly on the side that is disconnected, which is a long, complex and difficult process.
In particular, this process generally necessitates the provision of plant such as a crane to provide additional and temporary support for the overhead lines. It must be possible for each support 1 to be detached from the ground in order for the assembly that it supports to be moved away from the circuit-breaker 2 by a distance of the order of ten centimeters to release the circuit-breaker, whilst preventing the cable connected to the bushing causing significant tilting of the assembly caused by the high traction forces that the cable exerts on the crossmember, and therefore the resulting high torque on the support. For safety reasons, the additional and temporary support must not be live, which necessitates disconnecting at least the overhead line held by temporary support.
The invention solves the above problem by proposing an articulated support with lateral movement making it a simple matter to move high-voltage or medium-voltage electrical plant without additional plant, without necessitating the application of high physical forces, and with no risk of out of limits movement that could in particular cause the plant and its support to tip over.